1-{[O-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea herbicidal composition and use

ABSTRACT

This invention relates to a crop-selective, herbicidal agent 1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea, a method for the preparation thereof and a method for selectively controlling undesirable plant species in the presence of crops with the crop-selective sulfamoyl urea derivative.

BACKGROUND OF THE INVENTION

Sulfamoyl urea derivatives are described in U.S. Pat. Nos. 4,622,065,4,666,508, 4,696,695 and 4,741,762. The sulfamoyl urea derivativesdisclosed therein demonstrate herbicidal activity but do not provide ashowing of selective weed control in the presence of crops.

It is, therefore, an object of this invention to provide a1{[o-(cycloalkylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dialkoxy-2-pyrimidinyl)ureaderivative that is a highly effective herbicidal agent useful for theselective control of undesirable plant species in the presence of crops.

It is also an object of this invention to provide a crop selected1-{[o-(cycloalkylcarbonyl)-phenyl]sulfamoyl}-3-(4,6-dialkoxy-2-pyrimidinyl)ureaherbicide that exhibits at least a 2X margin of safety when applied tobroadleaf weeds and grasses growing in the presence of cereal grainssuch as barley, wheat, oats, rye and upland rice and at least a 4Xmargin of safety when used for the control of broadleaf weeds and sedgesin the presence of transplanted paddy rice.

It is another object of this invention to provide a method forselectively controlling undesirable vegetation in the presence of cerealgrains utilizing1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea.Among the undesirable weed species controlled by the above-namedsulfamoyl urea are sicklepod, Cassia obtusifolita; annual sedges,Cyperaceae annual; yellow nutsedge, Cyperus esculentus; flatsedge,Cyperus serotinus; arrowhead, Sagittaria pygmaea; purple nutsedge,Cyperus rotundus; bulrush, Scirpus spp.; morningglory, Ipomoea spp. andhemp, Sesbania exalta.

SUMMARY OF THE INVENTION

The present invention relates to the preparation of1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)ureaand a method for the selective control of undesirable plant species inthe presence of crops. It has been found that the above-said compound iseffective for the selective control of a variety of weed species in thepresence of cereal crops and is especially useful for controllingbroadleaf weeds and sedges in the presence of transplanted or paddyrice.

Additionally, it has been found that this compound1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)ureais unique amongst sulfamoyl urea derivatives in its superior margin ofsafety toward crop plants, especially rice plants and particularlytransplanted paddy rice plants.

In accordance with the invention,1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)ureamay be prepared by the reaction of 2-amino-4,6-dimethoxypyrimidine withchlorosulfonyl isocyanate in the presence of methylene chloride followedby treatment of the thus prepared reaction mixture with o-aminophenylcyclopropyl ketone and triethylamine in the presence of methylenechloride, to yield the desired compound.

The discovery that the selectivity in cereal grains, particularly rice,is obtained by the introduction of a cyclopropyl group on the carbonylfunction attached to the phenyl ring of a sulfamoyl urea derivative isunexpected. Moreover, the finding that this substitution also providesselective control of a variety of undesirable weeds, especiallybroadleaf weeds and sedges, in the presence of barley, wheat, oats andrye as well as rice, is surprisingly. Additionally, it is mostadvantageous to find that the development and/or maturation of severalundesirable grass plants, such as barnyardgrass and quackgrass, areseverely retarded, if they are not killed, when such grasses some incontact with1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)ureaduring crop treatment for control of broadleaf weeds and sedges in thepresence of cereal crops.

In practice, the above-said sulfamoyl urea may be applied to crops inthe form of a solid or liquid herbicidal composition, comprising aherbicidally effective amount of the sulfamoyl urea dispersed in aninert solid or liquid carrier. The formulations may be applied aspreemergence or postemergence treatments. However, for rice treatmentsit is generally most effective to apply the above-said formulationspreferably the granular formulations, as post transplant preemergencetreatments, i.e. applied to the soil or to the food water after the ricehas been transplanted, but prior to or shortly after the emergence ofweeds. The formulations may also be applied as preplant incorporatedtreatments.

The above-said formulations may also be applied as foliar applicationsto the cereal crops after the weeds have emerged, rendering thememinently suitable for use in weed control in barley, wheat, oats, ryeand direct-seeded rice.

Advantageously,1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)ureacan be formulated as a wettable powder, liquid flowable or granularformulation useful for application to the crops in which weeds are to becontrolled.

The wettable powder may be prepared by grinding together about 65% w/wof1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea;about 25.70% w/w of bentonite clay; about 6.0% w/w of sugar free sodiumbased sulfonates of modified kraft lignin (dispersant); about 3.0% w/wof an anionic surfactant such as diocytyl sodium sulfosuccinate (wettingagent); about 0.20% w/w of silicon dioxide and about 0.10% w/w of asilicone anti-foam agent.

For application of this wettable powder to the crops and the weedsgrowing among the crops, the wettable powder is generally dispersed inwater and applied as an aqueous spray thereto. Generally, theapplication of a sufficient quantity of spray to provide about 0.016 to1.0 kg/ha and preferably about 0.02 to 0.20 kg/ha of the above-said1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)ureais satisfactory for selectively controlling undesirable vegetation,particularly broadleaf weeds and sedges, in the presence of cerealgrains.

The above-said sulfamoyl urea derivative may also be prepared as agranular formulation by dissolving or dispersing the active compound ina solvent such as acetone, methylene chloride or the like and applyingthe toxicant solvent mixture to sorptive granules such as attapulgite,montmorillonite, corn cob grits, bentonite or the like. Generally,sufficient toxicant solution is applied to the granules to provide fromabout 0.20% w/v to 2.0% of toxicant in the granule. Higherconcentrations of toxicant on the granules can, of course, be preparedif desired. Sorptivity of the granules used is the major limitingfactor. The granules are usually applied to the soil or water in whichthe crops are growing, in sufficient amount to provide about 0.016 to1.0 kg/ha and preferably about 0.02 to 0.20 kg/ha of toxicant to thetreated crops area.

A typical flowable concentrate formulation can be prepared by grindingtogether about 20% to 60% by weight of the sulfamoyl urea, about 1% to5% by weight of the sodium salt of condensed naphthalene sulfonic acids,about 2% to 4% by weight of a gelling clay, about 2% by weight ofpropylene glycol and about 30% to 55% by weight of water.

The flowable concentrate is generally dispersed in water for applicationto the crop area in sufficient amount to provide the treated area withabout 0.016 kg/ha to 1.0 kg/ha and preferably about 0.02 kg/ha to about0.20 kg/ha.

The invention is further illustrated by the examples set forth below.

EXAMPLE 1 Preparation of o-aminophenyl cyclopropyl ketone

To 100 mL of a 1.0M BCl₃ solution in methylene chloride and 100 mL ofethylene dichloride is added 9.3 g (0.1 moles) of aniline at 0°-5° C.Following the addition of aniline, 10.0 g (0.15 mole) of cyclopropylcyanide is added to the mixture and thereafter 14.4 g (0.11 mole) AlCL₃is added portionwise thereto. The mixture is allowed to warm to roomtemperature and placed in a distillation unit. Methylene chloride isremoved by distillation from the mixture until the pot temperaturereaches 70° C. The remaining mixture is then refluxed overnight (18hours).

The reaction mixture is cooled in an ice bath and water is added to thecooled mixture. Enough water is added to dissolve the solids in themixture and then the entire mixture is extracted twice with 100 mL ofmethylene chloride. The organic extracts are combined, dried overanhydrous MgSO₄ and evaporated in vacuo to leave 9.3 g of yellow oil(70% real product) by NMR The reaction is illustrated as follows:##STR1##

EXAMPLE 2 Preparation of1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea

A solution of 1.78 g (0.0114 mole) of 2-amino-4,6-dimethoxypyrimidine in50 mL of methylene chloride is cooled to 0.5° C. in an ice bath and 1.0mL (1.62 g, 0.114 mole) of chlorosulfonyl isocyanate then added to thesolution. The resulting mixture is stirred for 30 minutes and a solutionof 2.66 g o-aminophenyl cyclopropyl ketone (70% real, 0.0114) and 2.6 mLtriethylamine (0.0187 mole) in 50 mL of methylene chloride then slowlyadded to the mixture. The resulting solution is stirred at ambienttemperature overnight (18 hours).

The reaction mixture is then evaporated in vacuo and the resultingresidue dissolved in 50 mL of methanol. The pH of the resulting solutionis adjusted to about pH 1 with 10% HCl and the solution permitted tostand. A white solid precipitate forms in the solution and is filteredand dried to give 3.8 g (70%) of the desired product, mp 170°-171° C.The reaction may be illustrated as follows: ##STR2##

EXAMPLE 3 Preemergence rice tolerance under upland conditions

The preemergence rice tolerance to the compound of the present inventionis exemplified by the following test in which rice seeds (cv Tebonnet)are planted in a steam pasteurized sassafras sandy loan soil with 1.5%organic matter in 4-inch square plastic pots with three replications.After planting, the pots are watered to field capacity and then sprayedwith a laboratory belt sprayer. The test compound is applied as anaqueous acetone mixture 50/50 v/v at rates equivalent to 1.0, 0.5, 0.25,0.125. 0.063, 0.032, 0.016 and 0.008 kg/ha. The treated pots are thenplaced on greenhouse benches watered and cared for according to normalgreenhouse procedures. Three to four weeks after treatment eachcontainer is examined and rated for herbicidal effect based on visualdetermination of stand, size, vigor, chlorosis, growth malformation andover-all plant appearance. The rating system used is as follows:

    ______________________________________                                                                  % Control                                           Rating   Meaning          (compared to check)                                 ______________________________________                                        0        No effect        0                                                   1        Trace effect     1-5                                                 2        Slight effect     6-15                                               3        Moderate effect  16-29                                               4        Injury           30-44                                               5        Definite injury  45-64                                               6        Herbicidal effect                                                                              65-79                                               7        Good herbicidal effect                                                                         80-90                                               8        Approaching complete kill                                                                      91-99                                               9        Complete kill    100                                                 ______________________________________                                    

In this example the following abbreviations are used in the reportedresults.

    ______________________________________                                        Abbreviation      Identity                                                    ______________________________________                                        PE                Preemergence                                                POST-T            Post-transplant                                             BYG               Barnyardgrass                                               CYPSE             Cyperus serotinus                                           G/HA              grams per hectare                                           KG/HA             kilograms per hectare                                       ______________________________________                                    

Results of this test are reported below.

    ______________________________________                                        Rice Selectivity (Preemergence)                                                                   Rate    Herbicide                                         Compound            kg/ha   rating                                            ______________________________________                                        1-{[ -o-(cyclopropylcarbamoyl)-                                                                   1.00    7                                                 phenyl]sulfamoyl}-3-(4,6-                                                                         0.50    7                                                 dimethoxy-2-pyrimidinyl)urea                                                                      0.25    5                                                                     0.125   1                                                                     0.063   0                                                                     0.032   0                                                                     0.016   0                                                                     0.008   0                                                 ______________________________________                                    

Rice Tolerance to Post-Transplant Applications Under Flooded PaddyConditions

The tolerance of transplanted rice to post-transplanted herbicideapplications is determined as follows: Two ten-day-old rice seedlings(CV. Tebonnet) are transplanted into a silt loam soil in 32 oz plasticcontainers with a diameter of 10.5 cm and no drainage holes. Aftertransplanting the containers are flooded and water level is maintainedat 1.5 to 3 cm above the soil surface. Three days after transplanting,the flooded soil surface of the containers is treated with the selectedaquaeous/acetone 50/50 v/v mixture containing the test compounds toprovide the equivalent of 1.0, 0.5, 0.25, 0.125, 0.063, 0.032, 0.016 and0.008 kg/ha of active ingredient. The treated containers are placed ongreenhouse benches, watered such that water level is maintained asstated above, and cared for according to normal greenhouse procedures.Three to four weeks after treatment the test is terminated and eachcontainer is examined and herbicidal effect rated according to theabove-noted rating system.

    ______________________________________                                        PADDY CONDITIONS - POST-TRANSPLANT                                            APPLICATIONS                                                                  Compound       Kg/ha   BYG     CYPSE  RICE                                    ______________________________________                                        1-{[ -o-cyclopropyl-car-                                                                     1.00    9       9      3                                       bonyl)phenyl]-sulfamoyl-                                                                     0.50    9       9      1                                       3-(4,6-dimethoxy-2-                                                                          0.125   9       9      0                                       pyrimidinyl)urea                                                                             0.063   8       9      0                                                      0.032   8       8      0                                                      0.016   5       8      0                                                      0.008   2       --     0                                       ______________________________________                                    

Preemergence Weed Control Under Flooded Paddy Conditions

Preemergence herbicidal activity under flooded paddy conditions onbarnyardgrass and Cyperus serotinus is determined as follows:Barnyardgrass seeds or Cyperus serotinus tubers are planted in the top0.5 cm of silt loam soil in 32 oz plastic containers with a diameter of10.5 cm and no drainage holes. Water is added to these containers andmaintained at 1.5 to 3 cm of above the soil surface for the duration ofthe experiment. The test compounds are applied as an aqueous/acetonemixture 50/50 v/v pipetted directly into the flood water to give theequivalent of 1.0, 0.5, 0.25, 0.125, 0.063, 0.032, 0.016 and 0.008 kg/haof active ingredient. The treated containers are placed on greenhousebenches and cared for according to normal greenhouse procedures. Threeto four weeks after treatment the test is terminated and each containeris examined and herbicidal effect rated according to the above-notedrating system.

Rice Safe Rate and Weed Control Rate

Rice safe rate is the highest rate (in g/ha) with a rice herbiciderating of 0 or 1. Weed control rate is the lowest rate in g/ha with aherbicide rating of 8 or 9.

    ______________________________________                                                       Rice    Rice                                                                  Safe    Safe    BYG    CYPSE                                                  Rate    Rate    Control                                                                              Control                                 Compound       PE      Post-T  Rate   Rate                                    ______________________________________                                                     (G/ha)                                                           1-{[ -o-(cyclopropyl-car-                                                                    63      500     32     16                                      bonyl)phenyl]sulfamoyl}-                                                      3-(4,6-dimethoxy-2-                                                           pyrimidinyl)urea                                                              ______________________________________                                    

Selectivity Margins

Selectivity margin is rice safe rate (g/ha) divided by weed control rate(g/ha) for each weed species (barnyardgrass and Cyperus serotinus). Thisis calculated using transplanted rice safe rates and again usingpreemergence rice safe rates. Although the PE rice planting method isnot used under flooded paddy conditions, this is a more extreme methodof evaluating physiological rice tolerance to these herbicides, as riceseedlings are exposed to the herbicides from time of seed germination.

    ______________________________________                                        Selectivity Margins                                                                       Rice Post-Transplant                                                                       Rice PE                                              Compound      BYG      CYPSE     BYG  CYPSE                                   ______________________________________                                        1-{[ -o-(cyclopropyl-car-                                                                   16       32        2.0  4                                       bonyl)pheny]sulfamoyl}-                                                       3-(4,6-dimethoxy-2-                                                           pyrimidinyl)urea                                                              ______________________________________                                    

EXAMPLE 4 Weed Control of Broadleaf Weeds and Tolerance of Wheat andBarley Postemergence

The postemergence herbicide activity and wheat and barley selectivity isdemonstrated by the following tests. Seeds or propagating organs of eachplant species are planted in separate cups, in a commercial artificialgreenhouse growth media composed of peat moss, vermiculite, sand andcharcoal (Metromix 350). Plants are grown in a greenhouse for about twoweeks. The plants are then sprayed with the selected aqueous acetonesolution containing test compound in sufficient quantity to provide theequivalent of about 0.004 to 2.0 kg/ha. These solutions also containapproximately 2 molar equivalents of diethylamine per molar equivalentof test compound, to add solubility of the test compound in the aqueousacetone solution. These solutions also contain 0.25% of a spreaderactivator such as alkylaryl polyoxyethylene glycol plus free fatty acidand isopropanol.

After spraying, the plants are placed on greenhouse benches and arecared for in the usual manner, commensurate with conventional greenhousepractices. Three to five weeks after treatment, each cup is examined andthe herbicidal effect is rated according to the rating system reportedin the previous example.

For the test of cereal tolerance, three pots are treated with eachtreatment, and data given represents average values for these threereplications.

    ______________________________________                                        Crop And Weed Species Employed In These Tests                                 Crops                                                                         Common Name And Variety                                                                             Scientific Name                                         ______________________________________                                        Rice cv. Tebonnet     Oryza sativa                                            Barley, winter cv. Barberouse                                                                       Hordeum vulgare                                         Barley, spring cv. Bonanza                                                                          Hordeum vulgare                                         Wheat, winter cv. Fidel                                                                             Triticum aestivum                                       Wheat, spring cv. Katepwa                                                                           Triticum aestivum                                       Wheat, durum cv. Wakooma                                                                            Triticum aestivum                                       ______________________________________                                    

    ______________________________________                                        Weed Species                                                                  Abbreviation                                                                              Common Name  Scientific Name                                      ______________________________________                                        BYG         Barnyardgrass                                                                              Echinochloa crus-galli                               CYPSE       Flatsedge    Cyperus serotinus                                    GALAP       Galium       Galium aparine                                       STEME       Chickweed    Stellaria media                                      TAROF       Dandelion    Taraxacum officinale                                 KCHSC       Kochia       Kochia scoparia                                      VIOAR       Field violet Viola arvensis                                       PAPSS       Poppy        Papaver sp.                                          MATIN       Mayweed      Matricaria inodora                                   PRUVS       Healall      Prunella vulgaris                                    VERSS       Speedwell    Veronica sp.                                         ______________________________________                                    

Tolerance Of Cereal Species And Varieties To Postemergence Applicationsof1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea

    ______________________________________                                        Visual Herbicide Rating According To The Rating                               System Reported Above                                                               Winter                                                                        barley   Winter  Durum   Spring  Spring                                       `Bar-    wheat   wheat   wheat   barley                                 kg/ha berhouse`                                                                              `Fidel` `Wakooma`                                                                             `Katepwa`                                                                             `Bonanza`                              ______________________________________                                        2.00  5.3      3.7     3.7     4.0     5.3                                    1.00  4.0      2.7     3.0     2.3     4.3                                    0.500 3.7      2.7     2.3     2.0     4.0                                    0.250 2.3      1.7     0.7     1.7     3.7                                    0.125 1.7      1.0     0.0     1.3     2.7                                    0.063 0.7      0.0     0.3     0.0     1.3                                    0.032 0.3      0.0     0.0     0.0     0.3                                    ______________________________________                                    

    __________________________________________________________________________    Control Of Weed Species Via Postemergence                                     Application of 1-{[ -o-(cyclopropylcarbonyl)phenyl]-                          sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea                                Using The Rating System of Example 3                                          Rate                                                                              Weed Species                                                              kg/ha                                                                             GALAP                                                                              STEME                                                                              TAROF                                                                              KCHSC                                                                              VIOAR                                                                              PAPSS                                                                             MATIN                                                                              PRUVA                                                                              VERSS                              __________________________________________________________________________    0.125                                                                             9    0    9    4    0    6   9    9    9                                  0.063                                                                             9    0    9    3    0    8   8    9    7                                  0.032                                                                             9    0    5    0    0    6   9    9    3                                  0.016                                                                             8    0    4    0    0    6   9    9    3                                  0.008                                                                             7    0    4    0    0    4   7    9    0                                  0.004                                                                             4    0    0    0    0    2   5    8    0                                  __________________________________________________________________________

We claim: 1.1-{[O-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea.2. An herbicidial composition comprising an effective amount of1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)ureaand an inert carrier.
 3. A method for the selective control ofundesirable vegetation in the presence of cereal crops which comprisesapplying to the foliage and stems of the crops and undesirablevegetation growing in the presence thereof or to the soil or watercontaining seeds or other propagating organs of the undesirablevegetation in which the crops are growing, an amount of a compound1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)ureaeffective for the selective control of the undesirable vegetationgrowing in the presence of the crops.
 4. The method according to claim 3wherein the undesirable vegetation is barnyardgrass, broadleaf weeds andsedges and the crops are barley, wheat, oats, rye or rice.
 5. The methodaccording to claim 3 wherein the compound is applied to the crops andundesirable vegetation or to the soil or water containing seeds or otherpropagating organs of the undesirable vegetation, at the rate of about0.016 kg/ha to 1.0 kg/ha of1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea.6. The method for the selective control of undesirable vegetation intransplanted or direct-seeded rice which comprises applying to thefoliage and stems or to the soil or water containing seeds or otherpropagating organs of the undesirable vegetation, after the rice hasbeen transplanted or after the direct-seeded rice has emerged from theground, a herbicidally effective amount of a compound having thestructure ##STR3##
 7. The method according to claim 6 wherein theundesirable vegetation is barnyardgrass, broadleaf weeds or sedges andthe herbicidally effective compound is applied to the foiliage of thecrop or the soil or water in which it is growing at a rate of about0.016 kg/ha to 1.0 kg/ha.
 8. The method according to claim 6 wherein thecrop is transplanted paddy rice and the compound is applied thereto atthe rate of from about 0.002 to 0.20 kg/ha.